1. Field of the Invention
This invention relates to video display techniques, and in particular to techniques for enhancing video displays associated with computers, especially microcomputers. The present invention specifically relates to video display enhancement techniques used in conjunction with computer driven graphical displays, such as those used with CAD or computer aided drafting software.
2. Description of the Prior Art
The conventional prior art approach to techniques for graphical video display enhancement is a technique called windowing in which the display, under operator and/or computer control, is overlaid by another display. Windowing may be used in a manner in which the overlaying display covers all, or only a portion, of the original display. The overlaying display may be a display of different or even the same information as the original display. The overlaying display may be at the same or a different magnitude or scale as the original display.
These conventional techniques may be used in a manner in which a portion of the original display may be overlaid by an enlarged replica of a smaller portion of that display in order to present to the operator a zoomed or magnified view of a portion of interest within the original display while continuing to display that portion of the original display in the background for reference (to the extent that such original display is not concealed by the overlaying display).
Such conventional video graphics enhancement techniques are typically cumbersome and therefore often under utilized. Such techniques also suffer from a severe disadvantage which further restricts their use. This disadvantage is that these techniques result in discontinuous displays, that is, interconnections between the normal or unenlarged display area and the zoomed or enlarged display area are concealed at least in part by the zoomed display.
The discontinuity of such conventional graphics enhancement display techniques is particularly disadvantageous in CAD or other graphics environments where the interconnection information may be vital to the operator.